The compound 3-hydroxyglutaronitrile (“3-HGN”) is a precursor for a variety of useful materials, such as pharmaceutically active compounds, diamines used in hair coloring, and monomers for high-strength fibers. It has conventionally been synthesized by treating epichlorohydrin (“ECH”) with an inorganic cyanide in water, producing 4-chloro-3-hydroxy-butanenitrile (also known as “chlorohydrin”) as an intermediate, as shown for example by F. Johnson et al, J. Org. Chem. (1962), 27, 2241-2243):

This process suffers from low productivity and byproduct formation. For example, Johnson et al reported 60% yield after about 54 hours reaction time at 10-11° C. and 48 hours of continual extraction with ethyl acetate. Significant byproducts (18%) included the intermediate 4-chloro-3-hydroxy-butanenitrile and 4-hydroxycrotononitrile.
A need thus remains for a process to synthesize 3-hydroxyglutaronitrile with increased productivity and selectivity.